Gas cartridge type spray gun with pressure reducing device for treating cultures

ABSTRACT

The invention relates to a gas-cartridge type spray gun consisting of three main portions of moulded plastic material comprising firstly a head carrying the gas cartridge, a pressure reducing piston and a discharge nozzle, secondly a neck and thirdly a reservoir with a large opening on which the sub-unit consisting of the first two parts can be removably threaded, whereas a casing in two parts may surround the neck to be used as a practical handle. The liquid to be sprayed can be thus easily prepared in the reservoir without the necessity of an independent container.

United States Patent Rouqui 1 Apr. 30, 1974 [5 GAS CARTRIDGE TYPE SPRAY GUN WITH 2.552.857 5/l95l Knapp 2.19 579 x E U E ED DEVICE FOR 2,631,891 3/I953 Kochncr et al. 239/272 X 2,730,093 1/1956 Neely 239/309 X TREATING CULTURES 3,092,330 6/1963 Ridenour et al. 239/530 X Inventor: Pierre Rouquie, Le Chesnay, France Assignee: Etablissements et Laboratories Georges Truffaut, be Chesnay, France Filed: July 12, 1973 Appl. No.: 378,670

References Cited UNITED STATES PATENTS 3/1950 Nicholson 222/399 X Primary ExaminerAllen N. Knowles Assistant ExaminerAndres Kashnikow [5 7] ABSTRACT The invention relates to a gas-cartridge type spray gun consisting of three main portions of moulded plastic material comprising firstly a head carrying the gas cartridge, a pressure reducing piston and a discharge nozzle, secondly a neck and thirdly a reservoir with a large opening on which the sub-unit consisting of the first two parts can be removably threaded, whereas a casing in two parts may surround the neck to be used as a practical handle. The liquid to be sprayed can be thus easily prepared in the reservoir without the necessity of an independent container.

3 Claims, 3 Drawing Figures PATENTED APR 3 0 I974 SHEET 2 [IF 2 GAS CARTRIDGE TYPE SPRAY GUN WITH PRESSURE REDUCING DEVICE FOR TREATING CULTURES The present invention relates to spray-guns in general and has specific reference to a gas-cartridge type spray-' gun incorporating a pressure-reducing device and intended for the treatment of agricultural and horticultural vegetables with insecticides, fungicides, weedkillers and the like, and also in the field of ornamental and other flower cultures. This spray-gun is provided with a pressure-reducing device in order to maintain a substantially constant pressure throughout the time necessary for emptying the reservoir or the operation of the apparatus, and is adapted to receive not only normal spray-nozzles but also low-output nozzles so that, by using a reduced yet concentrated treatment mixture or product to be sprayed, it is possible to carry out treatments equivalent to those applicable with conventional devices operating under normal output conditions and having a 7 to 8 times greater volume.

The primary feature characterising the spray-gun according to this invention lies in the fact that the body of the apparatus comprises three main portions of moulded plastic material, the first portion consisting of a head capable of withstanding relatively high pressures and formed with a lateral cavity for receiving a gas cartridge having its cap adapted to be perforated by a striker mounted in said head, with an opposite lateral nose adapted to receive a suitable spray nozzle, and with a flat base flange, the second portion consisting of a neck of which the top flange is adapted to be assembled with the flat base flange of said head and the bottom is outflared and adapted to be fitted to the top of the third portion, said third portion consisting of a reservoir having a relatively large top opening, said head and neck portions being surrounded by a casing consisting of a pair of half-shells adapted to constitute a handle for gripping the device by the aforesaid neck or by the casing portion surrounding the cavity containing the gas cartridge.

The shapes contemplated for the component portions or elements of the spray-gun according to the present invention, and notably for the head, have been selected with a view'to meet as far as possible the following requirements:

i. mass production, notably by moulding plastic materials;

ii. easy stripping of moulded parts during their manufacture;

iii. avoiding distortion during the cooling of moulded parts stripped from the moulds;

iv. rigidity of the assembly due not only to the curved contours of the parts but also to the mode of assembling them;

v. perfect fluid-tightness;

vi. strength considerably higher than currently admitted standards;

vii. saving raw-materials and reducing the weight of the spray-gun.

In order to afford a clearer understanding of this invention, a typical form of embodiment thereof will now be described by way of example with reference to the attached drawings, in which:

FIG. 1 is a sectional view of the head forming a onepiece moulding of reinforced plastic material;

PK]. 2 is a similar section showing the neck portion of the device, and a FIG. 3 is a fragmentary section of the spray-gun assembly, showing notably the portions illustrated in the preceding Figures assembled with the reservoir and surrounded by the casing consisting of a pair of halfshells, together with the pressure reducing device, the gas cartridge and the spray nozzle fitted in the head.

The head 1 designed for withstanding relatively high pressures has a substantially constant wall thickness to avoid any distortion when stripping the part from the mould. It comprises a flat base flange 2 adapted to be assembled with the top flange of the neck 16, as well as on the one side a cavity 3 for receiving the gas cartridge 4 adapted to be screwed therein, and on the other side an end piece 5 adapted to receive also by screwing the spray nozzle carrier 6 acting at the same time as an output regulating valve for closing and opening the outlet passage for the treatment mixture to be sprayed. The central portion of this spray nozzle carrier 6 is hollowed out for receiving a filter (not shown) of any suitable type, and the outer end of the carrier 6 is screw-threaded for fitting interchangeable spray nozzles 7 thereto, each spray nozzle 7 being of course specially designed for the specific treatment to be applied, such as insecticidal or fungicidal on the one hand, or weed-killing on the other hand. The bottom of the cartridge cavity 3 is adapted to receive by screwing a striker carrier 8 of which the striker proper 9 is adapted to perforate the cap of the gas cartridge 4 when the latter is screwed home in said cavity 3. The striker 9 may be hollow and constitute a passage for supplying gas to a relatively small-sectioned pressure chamber 10 of the pressure reducing device, in which chamber the upper, relatively narrow end of a hollow piston 11 is adapted to slide, the inner passage of this piston interconnecting the upper small pressure chamber 10 and the larger lower expansion chamber 12 of greater cross-sectional dimension, which opens into the base flange 2.

The inner end of end piece 5 communicates with a vertical passage 13 also opening through said flange 2 and having fitted therein a pipe extension 14 projecting therefrom to the bottom of the reservoir 15 through the neck 16. Finally, the flange 2 may comprise a vent hole 17 for a safety valve as described hereinafter.

The neck 16 has a flat top flange 18 adapted to be assembled with the flange 2 of head 1 and this flange has formed therethrough openings 19 and 20 registering with expansion chamber 12 and passage 13, respectively. It further comprises a hollow boss 21 containing a spring-loaded safety valve 22 for discharging or venting the gas in case of accidental jamming of the piston 11 of the pressure reducing device. The bottom flange of neck 16 is outflared considerably and formed with an internally screw-threaded skirt portion 30 adapted to be screwed to the upper, wide-open end of reservoir 15. It will be seen that the neck 16 is adapted to retain the double piston 11 of the pressure reducing device by its base and that its valve-receiving boss 21 is also designed and dimensioned for properly enclosing and retaining the safety valve 22 with its calibrated spring.

The head 1 and neck 16 are surrounded by, and enclosed in, a casing 23 comprising a pair of half-shells assembled by means of screw-rods or bolts 24 and collars 25. Externally, this casing 23 has a regular, smooth curved surface narrowing down at the neck level and comprising a pair of opposite lateral streamlined projections surrounding the one the gas-cartridge cavity 3 and the other the head end-piece 5. Internally, the ends of the casing projections may comprise parallel annular reinforcing ribs 26 bearing against the registering portions of head 1.

The reservoir comprises as already mentioned in the foregoing a relatively wide, outflaring top opening corresponding in size to the internally screw-threaded open base skirt of neck 16 and formed with an externally screw-threaded cylindrical portion engageable by said skirt, so that the reservoir 15 can be used separately for preparing the treatment mixture or liquid to be sprayed.

It is clear that between the three portions 1, 16 and 15 of the main body of the apparatus suitable sealing gaskets must be fitted during the assembly operation, such as a perforated washer 27 between portions 1 and 16 and an annular gasket 28 between the neck 16 and reservoir 15. In FIG. 3 this last-named annular gasket 28 is shown as being fitted to the bottom of a groove formed in the neck base between an inner depending circular projection 29 of this base and the internally screw-threaded outer skirt 30. The reference numeral 31 designates one or more vertical external reinforcing ribs moulded integrally with the neck 16 and comprising through holes 32 for the passage of said assembling screw-rods or bolts 24.

Of course, the specific form of embodiment of the invention which is shown in the drawings and described hereinabove should not be construed as limiting the field of the invention since various constructional modifications could be brought thereto without departing from the basic principles of the invention as set forth in the appended claims.

The mode of operation of the spray-gun according to this invention will be readily understood from the above description and therefore it is deemed sufficient to give only a brief summary thereof.

The easily separable reservoir 15 provided withvits large top opening may be used directly for preparing the vegetable treatment mixtures without resorting to intermediate containers and then transferring their contents into the reservoir. Thus, for examples, the treatment product (in powder or liquid form) may be poured into the reservoir 15, and then water is added thereto up to the top of the reservoir while stirring, if necessary, with a stick or rod to facilitate the dissolution or solution of the mixture. After fitting the filled reservoir 15 in proper fluid-tight relationship to the neck portion 16 and mouting the proper spray nozzle 7, the valve 6 being closed, it will only be sufficient to introduce the gas cartridge 4 into its cavity 3 and screw this cartridge home therein for causing the striker 9 to perforate its cap and thus pressurize the liquid in reservoir 15, the value of this pressure being kept substantially constant by the action of a piston 11 tending to be lifted by an increment in the pressure produced in the larger expansion chamber 12, so as to close the gas passage to the reservoir. The liquid under pressure is forced through the passage 14 and the spray nozzle advantageously of the low-output type whereby a device equipped with a reservoir of relatively moderate volume (for example a one-liter reservoir) can be operated substantially like a device of considerably greater capacity, such as a commercial 5-liter mixture apparatus having a total volume of the order of eight liters.

What I claim is:

1. Gas-cartridge type spray-gun incorporating a pressure reducing device, notably for the treatment of vegetables, characterised in that the body of the apparatus comprises three portions of moulded plastic material, the first portion consisting of a head capable of withstanding relatively high pressures with one lateral cavity for receiving the gas cartridge with the striker for perforating its cap and an end piece opposite to said cavity for receiving a spray nozzle, and a flat base flange adapted to be assembled with a corresponding top flange of the neck of the apparatus which constitutes the second portion thereof, said neck portion comprising a widened base adapted to be fitted to the relatively wide upper opening of the reservoir constituting'the third portion of the apparatus, said head and neck portions being surrounded by a casing consisting of two half-shells adapted to be used as a handle for gripping the apparatus by the neck or the casing portion surrounding the cavity enclosing the gas cartridge.

2. Spray-gun according to claim 1, wherein the head comprises a recess for slidably receiving a pressure reducing piston having a narrow upper portion and a wider lower portion separating a narrow pressure chamber constantly communicating with the cartridge cavity from a wider expansion chamber opening through the head base into said neck so as to ensure a substantially constant pressure, the inner space of said end piece adapted to receive the spray nozzle communicating with another passage opening into said neck and receiving an ejection clipper pipe extending to the bottom of the reservoir.

3. Spray-gun according to claim 1, wherein the central portion of the upper flange of said neck comprises a recess for mounting a spring-loaded safety valve the venting action of which takes place through an opening formed to this end in the head base flange which registers with said valve recess. 

1. Gas-cartridge type spray-gun incorporating a pressure reducing device, notably for the treatment of vegetables, characterised in that the body of the apparatus comprises three portions of moulded plastic material, the first portion consisting of a head capable of withstanding relatively high pressures with one lateral cavity for receiving the gas cartridge with the striker for perforating its cap and an end piece opposite to said cavity for receiving a spray nozzle, and a flat base flange adapted to be assembled with a corresponding top flange of the neck of the apparatus which constitutes the second portion thereof, said neck portion comprising a widened base adapted to be fitted to the relatively wide upper opening of the reservoir constituting the third portion of the apparatus, said head and neck portions being surrounded by a casing consisting of two half-shells adapted to be used as a handle for gripping the apparatus by the neck or the casing portion surrounding the cavity enclosing the gas cartridge.
 2. Spray-gun according to claim 1, wherein the head comprises a recess for slidably receiving a pressure reducing piston having a narrow upper portion and a wider lower portion separating a narrow pressure chamber constantly communicating with the cartridge cavity from a wider expansion chamber opening through the head base into said neck so as to ensure a substantially constant pressure, the inner space of said end piece adapted to receive the spray nozzle communicating with another passage opening into said neck and receiving an ejection clipper pipe extending to the bottom of the reservoir.
 3. Spray-gun according to claim 1, wherein the central portion of the upper flange of said neck comprises a recess for mounting a spring-loaded safety valve the venting action of which takes place through an opening formed to this end in the head base flange which registers with said valve recess. 